Bore hole declinometer



Feb. 12, 1963 A. P. ARMSTRONG BoRE HOLE DECLINOMETER 2 Sheets-Sheet 1Filed April 20, 1959 Feb. 12, 1963 A. P. ARMSTRONG BoRE HOLEDECLINOMETER 2 Sheets-Sheet 2 Filed April 20, 1959 United States PatentO 3,077,233 BORE RULE DECLINMETER Alan P. Armstrong, Westminster, Calif.(311 E. 11th St., Long Beach 13, Calif.) Filed Apr. 2t), 1959, Ser. No.897,509 6 Claims. (Cl. 17E-45) This invention relates to a bore holedeclinometer which will determine the amount of deviation of the borefrom the vertical by means of pulses or surges which are introduced intothe mud stream flowing into the bored hole from the surface; saidimpulses being recorded at the surface by suitable instruments fordetermining pressure variations. My invention consists primarily of anindicating assembly which is mounted in the tool string immediatelyabove the drilling bit. This indicating assembly produce pressure pulsesin the drilling mud stream which are proportional in duration to theangular devia-tion from the vertical of the bored hole. There is also apressure recording instrument at the surface which records the durationof pressure pulses in the drilling mud, this recording instrument beingcalibrated and readable in degrees of declination of the bored hole fromthe vertical.

An object of my invention is to provide a bore hole declinometer whichwill indicate the amount of declination of the bored hole from thevertical, this reading being obtained at the surface of the ground whilethe drilling of the well continues, and without the necessity ofremoving the drill string or bit from the well.

A further object of my invention is to provide a novel bore holedeclinometer which is activated by fluid pulses introduced into the mudstream by means of a mechanism actuated by the mud stream, thismechanism introducing readable surges or pulses in a flowing mud streamin the bore of a well while the drilling operation of the wellcontinues.

It is to be understood that my invention can also determine, record, orindicate other information at the bottom of a well other thandeclination, such other information consisting of bottom holetemperatures, pressures, acidity, etc.

Still another object of my invention is to provide a novel bore holedeclinometer which will reposition and reactivate itself after eachangular reading produced thereby, and without the necessity of removingthe declinorneter from the bored hole.

Other objects, advantages and features of invention may appear from theaccompanying drawing, the subjoined detailed description and theappended claims.

In the drawings:

FIGURE 1 is a fragmentary vertical sectional View of the upper portionof my declinometer.

FIGURE 2 is a fragmentary vertical sectional View of the lower portionof my declinometer.

FIGURE 3 is a fragmentary longitudinal sectional view of the pendulumcontrol mechanism of my declinometer. FIGURE 4 is a fragmentarylongitudinal sectional view of a modified form of pendulum mechanism.

FIGURE 5 is a digrammatic View of my declinometer in position in a well.

FIGURE 6 is a diagrammatic view of the recording apparatus at thesurface of the well.

Referring more particularly to the drawing, casing or open hole 1forming the bore of the well extends from the surface to the bottom ofthe well, all of which is usual and well known in the art. During thedigging of the bore 1 a tool string 2, consisting of pipe, extends fromthe surface to a drill collar 3, and a bit 4i is attached to the bottomof the drill collar again in the usual and well known manner. The toolstring 2 is threaded to the upper end of the drill collar 3, again inthe usual and well known manner. In rotary drilling, drilling mud ispumped through a pipe 5 and thence into a swivel head 6 which is mountedon the upper end of the drill string 2. This drilling mud ilows underconsiderable pressure to the bit 4 and then flows upwardly in the bore 1and back to the surface. Any pulse or wave in the lstream of drillingmud within the drill stream 2 would, therefore, be transmitted back tothe surface and could be there received as a pulse, and also variouspulses which are separated from each other could be timed. The drillcollar 3 is provided with a plurality of necks or constrictions 7 8,etc., adjacent the upper end thereof. In this instance, two suchconstrictions yor necks 4are shown and these are spaced vertically aknown distance for the purpose of producing a pulse or wave in thecolumn of drilling mud within the drill string 2, as will be furtherdescribed. A cylinder 9 is concentrically mounted in the collar 3 and isiixedly held in this position by means of a plurality of spiders orrings 1d. A cap or closure 9 is secured to the lower end of the cylinder9. This cap 9 is preferably formed of a flexible material. A tubularpiston rod 11 extends into the top of the cylinder 9 and this tubularrod has a piston 12 thereon which closely tits within the cylinder 9. Aguide 13 is mountedv on the upper end of the cylinder 9 and surroundsthe piston rod 11. A head 14 is provided on the upper end of the pistonrod 11 and this head is somewhat smaller lin diameter than the necks 7and 3. As the head 14 passes through the necks 7 and 3 it willmaterially restrict the flow of drilling mud which is passing downwardlythrough the collar 3 and will thus create a surge or pulse during thetime that the head 14. is positioned within a neck 7 and 8. The necks 7and ybeing spaced vertically with a bulge 7 between the necks, willcause a different time interval to be recorded as the head moves from 7to 7 than from 7 to 8; the time varying with the downward speed of thehead 14 as it is pushed downwardly by the ow of drilling mud within thedrill string 2. The varying speed of the head 14 is accomplished by` theflow of fluid through a certain port and orice, as will be subsequentlydescribed. Since the rod 11 is tubular it will tend to oat upwardly inthe column of drilling mud whenever that mud is quiescent, that is, whenthe Inud pumps are not operating and when there is no low of mud withinthe drill string 2.

At the surface, whenever a pulse is produced by movement of the head 1dthrough a neck 7 or S and the bulge 7', this pulse will be received in asuitable pressure receiving instrument 15, which instruments are wellknown in the art. Once the pulse is received the timing of the pulses isrecorded by the pulse timing instrument 16. Thus it is possible toreceive a pulse produced within the drill string 2 by movement of thehead 14 downwardly as described, but also to time the pulses pro-ducedin the restrictions 7 and 8 and the bulge 7. While I have only shown twosuch restrictions, it is obviously possible to provide additional spacerestrictions if it is found desirable or necessary.

The drilling mud will move into the chamber 17 above the piston 12 topush this piston downwardly within the cylinder 9. 12 is filled with oiland serves as a control means, as will be further described. A rod 19extends into the bottom of the tube 11 and is formed with a head orguide 20 at its upper end which slides freely within the tube 11.

A transverse Wall 21 in the cylinder 9 defines the lower wall of thechamber 18. A fixed orice 22 extends through the wall 21 into anotherchamber 23 within the cylinder 9 and below the chamber 18. A slide valve24 is mounted on the wall 21 and when this valve is moved transverselyof the wall it will open and close the orifice or port 22. In oneposition of the valve 24, as shown The space or chamber 18 below thepiston.

in FIG. 2, the port 22 is open. In another position of the valve, asshown in FlG. 3, this port is closed. A metering cylinder 25 dependsfrom the wall 21 and the bore of this cylinder extends upwardly throughthe wall 21 to the valve Z4, substantially as shown. rThe port 26 inthevalve 24 will permit oil to flow from the chamber 1B eitherthrough theorice 22 or into the calibrating cylinder 25, depending on the positionof the valve. A cylindrical plunger 27 within the cylinder 25 isprovided. witha pin 28 which projects through th bottom of the cylinder25.V A coil spring 29 is attached at one end to the pinZSand tends topull the pin and the plunger 27 upwardly in the cylinder 25. Anelongated slot or control orifice 3@ extends through the wall of thecylinder 25, and the plunger 27 controls the opening through the orifice3d and thus determines the rate of flow of oil through that orifice.When the control tube 11 is pushed downwardly by the circulating mud asoft rubber O-ring 31 on the inside of the tube 11 will engage the head2li), pushing the rod 19 downwardly to swing the lever 32 which ispivotally attached to the valve 2d, by means of a pin 32 on the valve24, which pin enters a hole in the bottom of the lever 32 thus movingthe port 26 over the Calibrating cylinder 25 and permitting the oil -inthe chamber 13 to pass first into the cylinder 25 and then out throughthe calibrated opening 3d. The pressure of the oil in the chamber 18will also move the plunger 27 and the pin 2d downwardly against thetension or the spring 29. The downward movement of the plunger 27 willvariably open the Calibrating orifice 3d, thus -determining the rate offlow of the oil from the chamber 13 into the lower chamber 23 and thuscontrolling the rate of downward movement of the piston 12 as well asthe head 1d, and thereby determining the time of movement of the head 14from the neck 7 to the bulge 7' and the neck d. The lever 32 ispivotally mounted on the lug 32a projecting inwardly from the cylinder9.

The maximum downward movement of the plunger 27 and the pin 28 iscontrolled as follows: A weight 33 is mounted on a ball joint 34, whichjoint is positioned within a transverse wall 35 within the cylinder 9. Acone 36, which has peripheral steps 37 thereon, is also attached to theball 34 and extends upwardly into the chamber 23. The cone 36 with itssurface steps is immediately below the pin 23, and the weight 33 willswing the cone 3d to one side, depending upon the inclination ofthebored hole from the vertical. When the pin 23 is now driven downwardlyby pressure of the oil within the chamber 25 the pin will strike one ofthe surface steps' 37 to limit further downward movement of the plunger2'7 and thus determine the maximum opening of the orifice 30 for theparticular inclination of the bored hole. It will thus be evident thatthe different inclinations of the tool in the ybored hole will variouslyposition the cone 36 to stop the pin 23 and the plunger 27 in acorresponding position, thus adjusting the oritice 30 and varying thetime of movement of the head 14 from the neck 7 to the neck S. This timeinterval between successive pulses received by the instrument at thesurface will be recorded on the time mechanism 16 and this time elementin turn can be translated into degrees of declination of the bored hole.

After the declination of the hole has been determined as stated above,the llow of drilling mud into the well is stopped. Since there is no mudflow, the piston 12 will be stationary; also there will be no oilpressure in the chambers 18 and 23. The oil in the chambers 1S and 23has a lower specific gravity than the mud column on the outside of thecylinder 9 and, consequently, the piston 12 and hollow rod 11 will belloated upwardly in the mud column. Since the tube 11 is hollow it willfloat upwardly in the mud column to its original position shown in FIG.1, and at the same time the spring 29 will pushl the plunger 27 upwardlyto substantially close the nass orifice Sil. At the same time the rod 19will also be pulled upwardly due to the friction of the head 2li withinthe tube 11, and also by engagement with the compressible rubber stop31. Thus shifting the valve 2dto the position where the ports 22 and 2eare aligned, as shown in FIG. 2, and thus returning the parts to astarting or position of zero declination. This is usually accomplishedby moving the bit d ofi of bottom and permitting the drilling string tohang vertically in the well. If the declination is excessive, furthermovement of the bit vertically or further drilling ahead might correctthe de- Iiciency and, if not, the bit can be removed and a whipstoclrinserted inserted which is usual and well known in the art.

A moditication of the pendulum mechanism is shown in FlG. 4 wherein aweighted hemispherical pendulum d@ is mounted in a gimbal ring 41. Theplunger 27 has a pin 42 depending therefrom and this pin is pivotallyattached to a link 43. The other end of the link 43 is pivotallyattached to a post lid which rises from the weight dll. Thus as thehemisphere di? moves in the ring i1 the plunger 27 will be pulleddownwardly to expose the orifice 3@ in the same manner as previouslydescribed.

In Operation Assuming that the bit lis being rotated by the drill string2 in the normal manner and is drilling ahead with drilling mudcirculated through the drill string 2, the drilnng mud will be underconsiderable pressure and this drilling mud will pass downwardly throughthe string 2 and thence into the top of the cylinder 9 and will pressagainst the top of the piston 12. The tube 11 will thus be moveddownwardly, as well as the head 14 on the upper end of this tube. Whenthe head 1d enters the neck 7 a surge or pulse is created in thedrilling mud which is transmitted to the top of the drilling string 2and will be received by the mechanism 15. As the head 1d moves from 7 to7' this time interval will be recorded on the instrument 16. The rate ofmovement of the head 1d during this interval is determined by the sizeof the port 22. The initial downward movement of the tube 11 will causethe soft O-ring 31 to engage the head 2li and will push the rod 19downwardly to shift the valve 2d from a position to open the port 22 toa second position to open the cylinder 2S. When the orifice 30 is nowopen the rate of movement of the head 14 will be changed and,consequently, the time interval of movement of the head 14 from 7' to 8will be dierent than the time interval from 7 to 7. This latter timeinterval is again indicated on the instrument 16 and can be calibratedto indicate declination of the hole. IThe downward movement of thepiston 12 has pushed oil in the chamber 18 downwardly and this oil firstpasses through the port 22 until it is shifted into the cylinder 25. Thefirst action of the incoming oil into the cylinder 25 is to push theplunger 27 downwardly to open the orifice 30 and permit the incoming oilto flow into the chamber 23. Meantime, if there is some inclination inthe bored hole the pendulum 33 will swing the cone 36 to one side,exposing the steps 37 thereon to the pin 2S. Downward movement of theplunger 27 will push the pin 28 downwardly until it engages one of thesteps 37; thus limiting further downward movement of the plunger 27 andlimiting the exposed portion of the orifice 3d. This constriction of theorice 3d will limit the rate of movement of the piston 12 and thusregulate the movement of the head 14 from the neck 7 to the neck 8. Thistime interval is recorded in the timing mechanism 16 and can betranslated into the declination of the hole which determines theposition of the pendulum 33 and the cone 3d. After a reading has beentaken and the amount of declination of the hole determined, the how ofdrilling mud will be stopped and the bit 4 isv raised oil of bottom sothat the drill string 2 hangs vertically in the well. The drilling mudhaving been-stopped, there is no pressure on the piston 12, whichrelieves pressure in the chambers 1S and 23. The spring 29 now moves theplunger 27 upwardly, releasing the pendulum 33 so that it in turn canagain hang vertically. The tube 11 will now l'loat upwardly in the mudstream and will also pull the rod 1 9 upwardly to shift the valve 24through the link 32 so that the ports 22 and 26 are aligned, as shown inFIG. 2. The tool is now ready for continued drilling and a repetition ofdeclination indication.

Having described my invention, I claim:

l. ln a bore hole declinometer a drill string in the bored hole, a biton the lower end of said drill string; a drill collar in said drillstring above said bit, said drill collar comprising the housing for ahole declinometer, said drill string having a column of drilling mudtherein, said drill collar having a plurality of superposedconstrictions therein, a piston rod mounted in said drill collar forvertical movement therein, a piston on said piston rod to be acted uponby the drilling mud to force the piston rod downwardly in the drillcollar, a head on said piston rod, said head being movable past saidconstrictions to create a pulse in the drilling mud, and pulse receivingmeans at the surface of the bore hole, and a means to retard thedownward movement of said piston and piston rod, a cylinder in saiddrill collar, said piston being slidably mounted in said cylinder, thedrilling mud bearing against one side of the piston, a wall in thecylinder, said wall-separating said cylinder into upper and lowerchambers, said wall having a fluid port extending therethrough to permitflow of a iluid from the upper to the lower chamber, pivotally mountedweighted means sensitive to the declination of the Ibore hole, and valvemeans connected to and operable by said weighted means con'- trollingthe size of said fluid port, stepped shoulders on the weighted meansengaged by the valve means, the opening of the fluid port by the valvemeans being approximately proportional to the tilt of the Weightedmeans, a second port in said wall, a second valve means controlling thesecond port, and means coupling the second valve means and said pistonrod to actuate the second valve means as the piston rod movesvertically.

2. In a bore hole declinometer a drill string in the bored hole, a biton the lower end of said drill string; a drill collar in said drillstring above said bit, said drill collar comprising the housing for ahole declinometer, said drill string having a column of drilling mudtherein, said drill collar having a plurality of superposedconstrictions therein, a piston rod mounted in said drill collar forvertical movement therein, a piston on said piston rod to be acted uponby the drilling mud to force the piston rod downwardly in the drillcollar, a head on said piston rod, said head being movable past saidconstrictions to create a pulse in the drilling mud, and pulse receivingmeans at the surface of the bore hole, and a means to retard thedownward movement of said piston and piston rod consisting of auniversally mounted weight, a head on the weight, a plurality of spacedstop shoulders on the head, said drill collar having a tluid porttherein positioned above said head, valve means movable over said portto constrict the port and reduce iluid ilow therethrough, said lastnamed valve means being engageable with and movable relative to any ofthe stop shoulders to permit movement of the valve means over said portand vary the opening thereof, the opening of the fluid port by the valvemeans being approximately proportional to the tilt of the weightedmeans, a second port in said wall, a second Valve means controlling thesecond port, and means coupling the second valve means and said pistonrod to actuate the second valve means as the piston rod movesvertically.

3. In a bore hole declino-meter a drill string in the bored hole, a biton the lower end of said drill string; a drill collar in said drillstring above said bit, said drill collar comprising the housing for ahole declinometer,

strictions to create a pulse in the drilling mud, and pulse receivingmeans at the surface of the bore hole, and a means to retard thedownward movement of said piston and piston rod consisting of a cylinderxedly mounted in said drill collar, said piston being slidably mountedin said cylinder, the drilling mud bearing against one side of thepiston, a transverse wall in the cylinder separating said cylinder intoupper and lower chambers, said wall having a metering cylinder therein,a plunger in the metering cylinder, said metering cylinder having ametering orifice extending through a wall thereof, said plunger beingmovable over the metering orifice to control the size thereof, andpivotally mounted weighted means sensitive to the declination of thebore hole, and spaced stop meanson said weighted means engageable bysaid plunger to limit the movement of the plunger relative to themetering orice, and control lluid ilow therethrough,.

the opening of the fluid port by the valve means being approximatelyproportional to the tilt of the weighted means, `a second port in saidWall, a second valve means controlling the second port, and meanscoupling the sec-l ond valve means and said piston rod to actuate thesecond valve means as the piston rod moves` vertically.

4. In a bore hole declinometer a drill strint7 in the bored hole, a biton the lower end of said drill string; ay drill collar in said drillstring above said bit, said drill` collar comprising the housing for ahole declinometer, said drill string having a column of drilling mudtherein, said drill collar having a plurality of superposedconstrictions therein, a piston rod mounted in said drill collar for`vertical movement therein, a piston on said piston rod to be acted uponby the drilling mud to force the piston rod downwardly in the drillcollar, a head on said piston rod, said head being movable past saidconstrictions to create a pulse in the drilling mud, and pulse receivingmeans at the surface of the bore hole, and a means to retard thedownward movement of said piston and piston rod consisting of a cylinderfixedly mounted in said drill collar, said piston being slidably mountedin said cylinder, the drilling mud bearing against one side of thepiston, a transverse wall in the cylinder separating said cylinder intoupper and lower chambers, said wall having a metering cylinder therein,a plunger in the metering cylinder, said metering cylinder having ametering orifice extending through a wall thereof, said plunger beingmovable over the metering orifice to control the size thereof, auniversally mounted weight in said cylinder, a head on the weight, aplurality of spaced stop shoulders on the head, and means projectingfrom said plunger, said means on the plunger being engageable with anyof the stop shoulders to control the size of the fluid port, and controllluid now therethrough, the opening of the fluid port by the valve meansbeing approximately proportional to the tilt of the weighted means, asecond port in said wall, a second valve means controlling the secondport, and means coupling the second valve means and said piston rod toactuate the second valve means as the piston rod moves vertically.

5. In a bore hole declinometer a drill string in the bored hole, a biton the lower end of said drill string; a drill collar in said drillstring above said bit, said drill collar comprising the housing for ahole declinometer, said drill string having a column of drilling mudtherein, said drill collar having a plurality of superposedconstrictions therein, a tubular piston rod mounted in said drill collarfor vertical movement therein, a piston on said piston rod to be actedupon by the drilling mud to force the piston rod downwardly in the drillcollar, a head on said piston rod, said headl being movable past saidconstrictions to create a pulse in the drilling mud, and pulse receivingmeans at the surface of `the bore hole, a second rod-extending into'said'tubular rod and slidable therein, a cylinder xedly mounted in thedrill collar, said piston being slidably mounted in said cylinder, thedrilling mud bearing against one side of the piston, a transverse wallin the cylinder separating said cylinder into upper and lower chambers;said wall having an orifice therein connecting said upper and lowerchambers, valve means in said wall adapted to open and close saidoriiice, actuating means connecting said Valve means and the second rodwhereby said valve means is operated, a metering cylinder on said wall,said valve means being movable to connect said upper cylinder and themetering cylinder, said metering cylinder having an oriiice thereinextending through a Wall thereof, a plunger in the metering cylinder,said plunger being movable over the metering orifice tocontrol the sizethereof and control fluid llow therethrough, a pendulum in saidcylinder, and means on the pendulum engageable-by-the plunger, to-limitthe movement ots-aid plunger in the metering cylinder, the opening ofthenidport bythe valve means being approximately proportional toV thetilt of the weighted means, a second port in saidz wall, a second valvemeans controlling thesecondsport, and means coupling the second valvemeans and said piston rod to actuate the second valve means as thepiston .rod moves vertically.

- 6. In a bore. hole declinorneter a drill string in the bored hole, abitonythe lowerend of said drill string; a drill collar in said drillstring above said bit, said drill collar comprising the housing for ahole declinorneter, said drill string having a column of drilling mudtherein, said drill collar having a. plurality of. superposedconstrictions therein, a tubular piston` rod mounted in said drillcollar for vertical movement therein, a piston on said piston rod to beacted upon by the drilling mud to force the piston rod downwardly in thedrill collar, a head on said piston rod, said head being movable pastsaid constrictions to create a pulse in the drilling mud; and pulsereceiving means at the surface of the bore hole, a second rod extendinginto said tubular rod and slidable therein,

a cylinder ixedly mounted in the drill collar, said pistonl beingslidably mounted in said cylinder, the drilling mud' bearing against oneside of the piston, a transverse wall in the cylinder separating saidcylinder intoupper and-lower chambers, said wall' having an orificetherein connecting said upper and lower chambers, valve meansv in saidwall adapted to open and close said orice, actuatingrality of spacedstop shoulders on the head, and meansprojecting from said plunger, saidmeans on the plunger being engagea'ble with any of thestop shoulders tocon-- trol the movement of the plunger over the metering` orice, theopening of the iuid port by the valve meansA being approximatelyproportional to the tilt of the weighted means, a second port in saidwall, a second valveV means controlling the second port, and meanscoupling the second valve means and said piston rod to actuate thesecond valve means as the piston rod moves-vertically;

References Cited in the tile of this patent UNTED STATES PATENTS1,854,208 Lynch et al Apr. 19, 1932 2,329,732 Varney et al Sept. 2l,1943 2,435,934 Varney et al Feb. 10, 1948 2,762,132 Varney Sept. 11,1956 2,824,380 Nelson Feb. 25, 1958' 2,953,350 Moore Sept. 20, 1960

2. IN A BORE HOLE DECLINOMETER A DRILL STRING IN THE BORED HOLE, A BITON THE LOWER END OF SAID DRILL STRING; A DRILL COLLAR IN SAID DRILLSTRING ABOVE SAID BIT, SAID DRILL COLLAR COMPRISING THE HOUSING FOR AHOLE DECLINOMETER, SAID DRILL STRING HAVING A COLUMN OF DRILLING MUDTHEREIN, SAID DRILL COLLAR HAVING A PLURALITY OF SUPERPOSEDCONSTRICTIONS THEREIN, A PISTON ROD MOUNTED IN SAID DRILL COLLAR FORVERTICAL MOVEMENT THEREIN, A PISTON ON SAID PISTON ROD TO BE ACTED UPONBY THE DRILLING MUD TO FORCE THE PISTON ROD DOWNWARDLY IN THE DRILLCOLLAR, A HEAD ON SAID PISTON ROD, SAID HEAD BEING MOVABLE PAST SAIDCONSTRICTIONS TO CREATE A PULSE IN THE DRILLING MUD, AND PULSE RECEIVINGMEANS AT THE SURFACE OF THE BORE HOLE, AND A MEANS TO RETARD THEDOWNWARD MOVEMENT OF SAID PISTON AND PISTON ROD CONSISTING OF AUNIVERSALLY MOUNTED WEIGHT, A HEAD ON THE WEIGHT, A PLURALITY OF SPACEDSTOP SHOULDERS ON THE HEAD, SAID DRILL COLLAR HAVING A FLUID PORTTHEREIN POSITIONED ABOVE SAID HEAD, VALVE MEANS MOVABLE OVER SAID PORTTO CONSTRICT THE PORT AND REDUCE FLUID FLOW THERETHROUGH, SAID LASTNAMED VALVE MEANS BEING ENGAGEABLE WITH AND MOVABLE RELATIVE TO ANY OFTHE STOP SHOULDERS TO PERMIT MOVEMENT OF THE VALVE MEANS OVER SAID PORTAND VARY THE OPENING THEREOF, THE OPENING OF THE FLUID PORT BY THE VALVEMEANS BEING APPROXIMATELY PROPORTIONAL TO THE TILT OF THE WEIGHTEDMEANS, A SECOND PORT IN SAID WALL, A SECOND VALVE MEANS CONTROLLING THESECOND PORT, AND MEANS COUPLING THE SECOND VALVE MEANS AND SAID PISTONROD TO ACTUATE THE SECOND VALVE MEANS AS THE PISTON ROD MOVESVERTICALLY.